The present invention relates to a semiconductor device and a method of manufacturing the semiconductor device. Specifically, the invention relates to a technique effectively applied to a semiconductor device including a fin field effect transistor.
A fin field effect transistor is known as a field effect transistor capable of reducing leakage current and power consumption and being fined while operating at high speed. The fin field effect transistor (FINFET) is, for example, a semiconductor element that has a channel layer including a pattern of a semiconductor layer formed over a substrate, and has a gate electrode formed so as to straddle the pattern.
The electrically erasable and programmable read only memory (EEPROM) is widely used as an electrically writable and erasable, nonvolatile semiconductor memory device. Such a memory device typified by a currently widely used flash memory has a conductive floating gate electrode surrounded by an oxide film or a trapping insulating film below a gate electrode of a MISFET, uses a charge storage state in the floating gate or the trapping insulating film as memory information, and reads the charge storage state as a threshold of the transistor. The trapping insulating film refers to a charge-storable insulating film, and includes, for example, a silicon nitride film. Electric charges are injected or emitted into/from such a charge storage region to shift the threshold of the MISFET that is thus allowed to operate as a memory element. Such a flash memory includes a split gate cell using a metal-oxide-nitride-oxide-semiconductor (MONOS) film.
Japanese Unexamined Patent Application Publication No. 2013-42067 describes a formation process of a fin field effect transistor, in which a silicon oxide film (liner film) is formed in a trench between fins, and then a polysilazane (PSZ) film is formed by application in the trench, and the PSZ film is successively nitrided and oxidized to form a SiON film, so that the element isolation region is formed by the SiON film and the silicon oxide film.